|A highly regarded expert|
Point Blank Shot, Precise shot, and Weapon Focus (Ray)- Even ranged touch attacks miss. The question is, how often do they miss by exactly 1 or 2? How often do you use them? Is it worth two or three feats? Considering all the feats that will do far more for you to keep you alive and contributing, the answer is no. Big creatures have horrible touch ACs as a general rule, and even at a minus, you can usually hit. It isn’t like the old days, when a miss could hurt your allies. You got, or will get a belt, right?
Better to miss with a ray, than hit and watch it not work (Spell Penetration), or fail a fort save (Greater Fortitude), or get slaughtered because you thought you’d make it to 16th level without any armor (Arcane Armor Training). Sneak blasting is a fun feature of your character, but it’s not your raison d'être. It’s not that great.
I don't see any need for Alertness. Take Toughness, instead. Scouts need hit points worthy of their role.
Since you're starting at high level, ignore AAT. That's for surviving low level play, until you have +8 bracers.
Get a wand of True Strike and use it when you have the time. That won't be often, but it helps a lot when you can.
It's better to have Spell Penetration so that when you hit, the spell actually works.